Machine for drying photographic films and the like



J. W. SMITH A ril 27, 1937.

MACHINE FOR DRYING PHOTOGRAPHIC FILMS AND THE LIKE Filed June 28, 1955 3 Sheets-Sheet 1 "10 oer- NVEIY'TOR John VS/fgfim 5%.

. WATTORNEY April 27, 1937. J. w. SMITH 2,078,292

MACHINE FOR DRYING PHOTOGRAPHIC FILMS AND THE LIKE Filed June 28, 1935 3 Sheets-Sheet 2 INVENTOR WITNESS 8) 4.

' HTTOR/VEY April 27, 1937- J. w. SMITH 2,078,292

MACHINE FOR DRYING PHOTOGRAPHIC FILMS AND THE LIKE Filed June 28, 1935 3 Sheets-Sheet 3 nrroR v r Patented Apr. 27, '1937 UNITED STATES PATENT T OFFICE MACHINE son name rno'rocmirmc FILMS AND THE LIKE John Wesley Smith, Chesnut Hill, Pa, assignor to .Phlladelphia Air Transport Company,v Norristown, Pa., a corporation of Pennsylvania Application June 28, 1935, Serial No. 28,788 vs Claims, (01. 34-48).

.iury to their surfaces. However, since the inven-' I tion, as stated, is of particular advantage in drying large size photographic films, I shall herein describe it in connection with a preferred form of machine adapted for that Purp se.

The time required to satisfactorily dry 9. photographic film after development-which term is herein employed comprehensively to include not only the actual development itself but also the customary subsequent fixing and washing operations--byithe methods heretofore in vogue is considerable; a -thlng, highly objectionable in many classes of photography, such as military or commercial aerial photography, X-ray work and the like in which it is essential to have the exposed film developed, dried and thereby placed in condi tion for printing or other use in the shortest possible tima An object of the present invention, therefore, is the provision of novel means for rapidly and eillciently d y ng photographic films and like articles in aminlmum of time without injury to their surfaces if, as in the case of film, of delicate nature.

A further object of the invention is to provide means of the character aforesaid which are compact and of relatively light weight, thereby facilitatin g'transportation in aeroplanes, automobiles or the like from place to place and employment wherever a suitable source of electric current is available.

Still further objects of the invention are to provide a machine for drying films or the like which is substantially automatic in operation during the major portion of the drying period;

T which is so constructed as not to be liable to get out of order or become damaged under conditions of use to which it may be subjected in field and like work,.a'nd which is operative to deliver the dried film properly wound upon a spool of the type ordinarily used for holding photographic Other objects, purposes, advantages and novel features of design, construction and arrangement of elements comprehended by the invention are hereafter more particularly pointed out or will be apparent to those skilled in the art from the following description of one form of drying machine constructed inaccordance therewith and illustrated in the accompanying drawings in which: 5

Fig. 1 is a front elevation of the machine;

Fig. 2 is a rear elevation thereof;

Fig. 3 is an end view of the machine looking to the right in Fig. 1;

Fig. .4 is a vertical section thereof substantially 10 on the line 4-4111 Fig. 1;

Fig. 5 is' an enlarged fragmentary detail view,

. partially in section and partially in side elevation,

of the film gate and adjacent parts with the gate in-closed or normal position;

Fig. 6 is a corresponding view showing the gate raised preparatory to inserting the film;

Fig. 'I is an enlarged fragmentary end elevation partially in section of the-roller drive and associated parts;

Fig. 8 is a side elevation thereof partially in fragmentary section;

Fig. 9 is a detail view of part of sioning means;

-Flg.- 10 is a plan view of the film guide clip with the film in position therein, and

Fig. 11 is an end elevation thereof.

Throughout the drawings the same characters of reference are used to designate the same parts.

Photographic film comprises a substantially non-fiuid-absorbent base coated on one side with a fluid-absorbent emulsion which, after development, is substantially saturated with the fluid, generally water, in which the film has last been immersed. On mere exposure to the air this fluid gradually evaporates until the emulsion is entirely dry and relatively hard and the film therefore in condition for printing or the like.

the belt ten- T The evaporation of the fluid may be hastened by subjecting the emulsion side of the film to a blast of air but I have found the effect of such a blast is markedly localized to the area in which it directly impinges on the film and that on both sides of this area the evaporation takes place much more slowly despite the fact that it is n traversed by the air from the blast as it moves along the film laterally in opposite directions from the area initially contacted and substantially in line with the nozzle from which-it is prolected. It therefore results that in order to obtain maximum rapidity of evaporation each point on the emulsified surface of the film must be sub- Jected to the direct action of the air blast so that if but a single nozzle were employed the whole film, which is generally many feet in length,

' would have to be moved progressively past it at a rate sufiiciently slow to insure adequate drying of the emulsion, an operation which would necessarily consume a large amount of time although probably less than that requisite to dry the film by simple exposure in still air of corresponding temperature.

Therefore, in the preferred practice of my in vention I provide a plurality of air nozzles in association with means for simultaneously directing a strong blast of air through each of raphy whch are usually about 9 wide and of a minimum length of at least ten feet. The development of these films. may be conveniently secured to' the adjacentframe members by bolts 1 and also, through the medium of a marginalfiange 8 carried by the mottir body, to the adjacent face of a drum generally designated l0 and hereinafter more particularly described. As best shown in Fig. 4,- the motor body -extendsinto the drum for a short distance and the motor shaft I I extending therebeyond carrieswithin the drum a fan l2 having a plurality of blades l3 arranged to draw air axially into the drum from the rear side thereof and to discharge it within the drum. 7 The specific arrangement and design of the fan blades is a matter 'of choice as long as the fan is adapted for the performance of itsintended function with maximum efiiciency-and a minimum expenditure of power, as is also the particu lar type of motor employed.

The drum comprises generally annular front.-

- and rear plates I5, I 6, theformer being cut out at effected in an apparatus substantially of the character .patented to me in Letters Patent clusion of the development is therefore wound on one .of the spools-or reels comprised in the, apparatus or, if other apparatus be employed, on an ordinary film spool. In the former case the reel and its supporting frame after removal from the developing tank are disposed adjacent the drying machine with the axis of the reel;

horizontal so that the film can be drawn therefrom as the reel or spool S rotates, or if the film 1,860,059, granted May 24, 1932, and at the conbe wound on an ordinary film holding spool, the

latter is similarly disposed adiacentthe machine on a suitable support s in which it can readily revolve so the film F can be drawn to the machine with its emulsion side e uppermost. The specific means for supplying the film to, the drying machine, however, form no part of the in,-

vention and aretherefore a matter of choice so long as they are effective to deliver the film thereto emulsion side uppermost as just described.

The machine itself comprises a generally rectangular base -I from the opposite ends of which and nearer one side 'of the base than the other rise oppositely inwardly directed supports 2, 3 which are united at their upper extremities and between which extends a horizontal brace 4 disposed about midway between the upper ends of the supports and the base, while to stiffen the structure struts 5 are .interposed between the supports near their lower ends and the remote side of the base. The various parts just described are preferably made of light steel'tubing desirably united by welding and thus form a frame adapted to rigidly support the other parts of the machine in assembled relation, the disposition of the supports 2, 3 with respect to the base being such that the weight of the machine as a whole is distributed substantially equally on the base to thereby negative any tendency of the machine to tip one way or the other and insure its remaining in upright position even though the base be disposed on a supporting surface which is uneven or slightly inclined from the horizontal as is often the.case'w hen the apparatus is employed in field work.

The supports 2, 3 and brace l define a substantially isosceles triangle through which extends the body of an actuating motor 6 suitably its center to accommodate the motor and the latter being similarly cut to accommodate the adjacent end of the fan, the fan opening being preferably surrounded. by an inwardly directed flange I! to minimize air leakage. The plate I5 is supported from motor flange 8 and also by' bolts extending from supports 2, 3 and-carrying spacer sleeves l8 between'the latter and the plate, while the rear plate I6 is braced by a bracket l9 extending between its lower part and the adjacent member of the base, both plates thus lying 'parallel to each other in vertical laterally spaced plane's.

As best shown in Figs. 5 and 6, the outer peripheral edge of each plate is'so formed as to provide a plurality of substantially semicircular relatively small cutouts 'or scallops respectively alignedwith those in the opposite plate, a small rectangular radially directed tab of metal being preferably initially left at the bottom of each cutout. These cutouts form seats for the extremities of transversely extending generally semicircular channels 20 the extremities of which are indented opposite the tabs 24 to receive the latter which arethen slightly headed or bent over to assist in holding the channels in position and, if desired, the ends of the channels may be soldered or welded to plates l5, Hi to further secure them in place. The channels and cutouts just described are so proportioned that after assembly a narrow opening or nozzle 22 extending from one side.

plate to the other is formedbetween each adi jacent pair of the semicircular channels 20.

It is thus apparent that the periphery of the drum comprises a large number of nozzles 22 which are preferably arranged as closely together Y as is conveniently possible with due regard for structural considerations and the like, so that when the fan is in operation a. corresponding number of jets of air will be projected outwardly from the drum in a generally radial direction. To assist in directing to the nozzles the air discharged by the fan and to minimize undesirable turbulence within the drum, a series of baffles 25 of suitable configuration are extended transversely of the drum in annularly spaced relation between the fan and the nozzles and suitably secured to the side plates of the drum in any convenient way.

It will be noted from Figs. 5 and .6 that at one point, preferably near the gate hereinafter described, a somewhat wider cutout than usual is made at the edges of the plates and a correspondingly widened channel 20' located therein and secured to side plates l5, l6 by screws extend ing through ears 20'. bent down'from its extrembeing thus removable to afford a means of access to the interior of the drum should the occasion arise.

vIn theoperation of the machine the film 1 drawn from the spool S is progressively moved about the drum by mechanism now to be described, whereby its emulsion side e while facing the drum but maintainedout of contact therewith by the force of the air jets is progressively subjectedto the action of the latter for a period suflicient to adequately dry it.

The said mechanism consists essentially of a plurality of circumferentially spaced rollers 30 mounted on annular supports 3|, .32 respectively spaced slightly outwardly of side plates l5, l6 and supported therefrom by brackets 33. These annular roller supports are of somewhat greater diameter than the drum'so that the rollers, each of which has a small axial pin at each end journaled in a bore in the adjacent support, are spaced slightly outwardly from nozzles-22, a sumcient number of rollers being provided to insure adequate support for the film and negative any material tendency of the latter to bulge out between them. The rollers are preferably disposed symmetrically about the drum save the two designated at 3B, 30" adjacent the point at which the film enters and leaves the cage formed by those between the others.

As hereafter more fully explained,the film during the drying operation is carried over roller 30' emulsion side up, thence around the drum with its emulsion side adjacent thereto and its back against the other rollers until it reaches roller 30" about which it is doubled back on itself, thus again bringing the emulsion side uppermost, and is then carried to a receiving spool R to the barrel of which the end of the film is secured and upon which it is progressively, wound as it is dried, this spool being detachably sup ported in brackets 35, 36 mounted on annular roll supports 31 3 2, and driven as hereinafter described.

In order to free the emulsified surface of the film from'excess water as well as to insure the proper lead of'the film over roller 30' as it en- 'ters the machine, I prefer to dispose adjacent that roller a swinging gate 40 carrying a pair of transversely extending idler rolls 4|, 42 provided at their front ends with side flanges 4|, 42' to assist in guiding the film.

This gate comprises a pair of laterally spaced side members 43 respectively aligned with and and the next subjacent roller and roll 42 being similarly generally aligned with the space between that roller and the next subjacent one as best shown in Fig. 5. Members 43 are tied together by a preferably hollow cross bar 44 dis-' posed between the rolls and at their upper extremities have inwardly directed lugs 45 whose extremities are pivoted to the adjacent annular supports, while at their lower ends the members carry spring clips 46 which engage the outer faces of the annular supports when the gate is lowered and yieldingly hold the latter in position; if desired, each clip may be indented from its outer face to form a boss or detent on its inner face adapted to seat in acorresponding depression 41 in the annular support. The gate is thus capable of being lowered to and yieldingly held in the position shown in Fig. 5 or swung upwardly temporarily as shown in Figlfi to permit the film to be passed over roller 30"; when the gate is thereafter lowered rolls 4l, 42 press inwardly against its emulsified face and serve to wipe oif any surface water adhering thereto which, if not reemulsified face of the film has no inimical efiect thereon.

Means are provided for rotating rollers 30 during operation so as to-progressively carry the film about the drum, said mmns being preferably employed as well; for driving receiving spool it so as to wind the dried film thereon. In the particular embodiment of the invention shown, said .means comprise around endless belt 50 disposed adjacent annular roller support 3| and engaging in grooves 5| near the adjacent extremities of rollers 30. This belt 'lies outside and preferably near the front ends of the rollers and to insure its remaining in proper position with respect thereto, guide pins .52 may be associated with brackets 33 extending from plate i 5 to project slightly above the belt. I The beltalso-extends upwardly and inwardly over a sheave 53 disposed below the motor and secured on a horizontal stub shaft 54 journaled in a gear housing 55 conven iently hung from brace 4 and suitably secured.

thereto (Figs. '7 and 8). Within this housing is disposed a wormgear 55 also secured to shaft 54 and meshing with a worm 51 on a horizontal shaft 58 jourhaled in the bottom of the housing and at one end of the worm shaft is keyed or otherwise secured a friction disk 59 disposed in a disk case 60 secured to that portion ,of the gear housing enclosing the worm; the opposite end of worm shaft 58 engages a spring pressed ball 6| so that theshaft is capable of a little longitudinal movement. The cover 52 of the. disk case is horizontally slotted and provided on its inner face with gibbs 63 which overlie a sliding plate 64 carrying a fork 65 engaging in a groove in a sleeve 66 carrying a friction pinion 61 engageable with friction disk 59. This sleeve is keyed to and slidableon a horizontal shaft 10 journaled in the disk case and extending parallel to the motor shaft H though'of course at a considerable distance below the latter, while the position of the fork is controlled by an operating knob H having its inner end of reduced diameter ext-ending through the slot in cover62 and threaded into plate 64. Thus, when the knob is slightly backed ft, the plate, forkand sleeve 66 can be moved longitudinally of shaft Ill to adjustably locate pinion 61 with respect to the face of disk 59 af't' which the knob is screwed in to hold the pinion in the selected position. An adjustable friction drive from shaft 10 to worm 51, worm gear 56, sheave 53 and belt 50is thus provided;

the speed of the belt and thus the speed'at which rollers 30 are driven being controlled by the position of pinion 61 with relation to disk 55;), while the direction of the drive may be reversed by carrying the pinion over the center of the disk if such reversal be desired. A stop screw 12 having a knurled outer end generally corresponding .ment of the pinion with respect to the disk.

The outer end of shaft 10 carries a pulley 13 from which a belt 14 passes upwardlyto a sheave on or groove in motor shaft II to thereby drive shaft I whenever the motor is in operation, and

means are preferably provided for'maintaining" a suitable tension on belt 50 at all times and may be of any suitable construction, those shown comprising a swinging arm 15 mounted on the boss of housing 55 through which shaft 54 extendsand carrying at its free end .a sheave I6 which is pressed against beltjitthrofigh the influence J LasSpring "ll 'coiledabout the boss.

Belt 50 is also conveniently employed to drive spool R, which as hereinbefore mentioned is removabiy mounted between brackets 35, 36 carried by annular supports 3|, 32. One of these brackets, preferably bracket 36 adjacent h nt/5.0 is made stationary and iieother provilfid with a ,spring -pressed hinge 80 so. arranged as to normally yet yieldingly hold it upright but adapted to permit it to be swung outwardly when spool R is being inserted or removed. This bracket carries on its inner face a stationary stud suitable to enter the axial bore of the spool and form a pivot therefor, while a dog clutch of usual design is disposed at the inner end of a shaft 8| journaled in a boss in the stationary bracket 36 for engagement in the complementarily formed opposite end of the spool bore sdas to turn the spool when it is supported between the brackets and the shaft is rotated in a mannern generally similar to that commonly in use for turning theifilmrreceivingspoolhifilm cameras which thus requires no further description.

Shaft 8i carries a grooved pulley 82 and the bracket also supports a small grooved idler pinion 83 adjacent thereto, and belt 50 is carried up over this pinion and between it and the pulley, as best shown in Fig. 1, so as to drive the latter and in turn shaft 8| and spool R when the belt is moved.

To facilitate the introduction of the film and to guide it initially during its movement about the drum, from roller 30" to roller 30, I prefer to attach to its leading end a guide clip' of suitable type, that shown in Figs. 10 and 11 being well adapted for the purpose. This clip 85 consists of a plate of thin metal approximating the width of the film and curved in general conformity to the arc defined by the annular roller supports. Its forward or leading edge is turned back on i itself to overlie .the ends of a U-shaped wire bail 86 the free portion of which thus'lies yieldingly against the upper surface of the plate so that by lifting it slightly the leading end of the film can be entered beneath it and gripped against the plate after the bail is released. The guide clip can thus be readily attached to the film preparatory to introducing it to the machine so as to prevent theend of the film from curling up and catching. in channels 20 or other parts during its passage about the drum. A clip ofthe character illustrated and just described is ordinarily well suited for the fulfillment of its intended function, but various other types of clips may be employed if preferred.

ao'a'aiaaa Operation The motor is first connected to a suitable source of current as by a flexible cable 90 having a which the wet film is wound is then brought to the machine and placed on a suitable support somewhat below, aligned with and in front of gate 40 with the spool axis substantially horizontal; "Alittle of the film is next drawn ofi,

emulsion side up, and the guide clip, if one is used, attached to its leading end. The gate is now raised and.the guide clip, carrying the film inserted over roller- 30" with the convex side of the plate adjacent thereto and then pushed down for a short distance over subjacent rollers 30'so as'to give the back of the film a bearing on a number of them;lthe gate isthen closed and the current is switched on the motor so as to drive the fan and also belt 50 through the medium of the friction drive associated therewith.

,Almostinstantly strong'jets of air are projected radially outward from the drum through nozzles 22 and those in the sector adjacent the film below roller 30" impinge on its emulsified surface e and force the film against the rollers lying outwardly of it; These rollers, as well as. all the other rollers 30 engaged by belt 50, are now in motion at a speed determined by the adjustmert of pinion 61 with respect to 'friction disk 58 -with the result that the film is moved progressively forward about the interior of the cage formed by the rollers, although -held' out of contact with fiozzles 22 by the pressure of the air jets, until its leading end with which the guide clip is associated reaches roller 30', that portion of the film within the machine then conforming substantially to the arc of a circle to which the rollers are tangent. As the clip reaches roller 30, the operator grasps it and as soon as a suitable length of film has emerged from beneath the roller turns the film upwardly and back over the latter so as to bring the emulsified surface e uppermost and the back of the film against the upper surfaces of rollers 30 above roller 30', and as soon as a sufiicient amount of film has passed the latter, he removes the clip and attaches the end of the film to the barrel of spool R, which has meanwhile been rotating under the drive of belt 50 but which may be temporarily stopped by holding it firmly and allowing the belt to slip on pulley 82 while the end of the film is being secured to it, in such manner that subsequent ro-- tation of the spool in the direction of the arrow in Fig. 1 will wind the film upon it.

It will now be apparent that each point on the film during its passage from roller 30" to roller 30' is consecutively subjected to the action of a plurality of closely associated air jets extending from one of the film edges to the otherand so directed as to impinge on the emulsified surface of the film substantially normal thereto. It"

fan at the rate at which it is driven, with the result that the film can be-thoroughly dried when moved about the drum at a comparatively rapid rate. In practice, this rate should be varied in conformity with prevailing conditions since if the machine is being operated on a hot dry day, the

film can be moved faster than when the air is cool and/or contains a high degree of moisture. By observing the condition of the film as it leaves roller 30 the operator can readily determine if its rate of travel can be increased so as to shorten the drying period or should be decreased so as to lengthen it, and by suitable adjustment of pinion 6! with respect to friction disk 59 can readily make the necessary corrections so as to bring about the maximum rate of film travel commensurate with having the film thoroughly dry by the time it reaches spool R.

As the film is progressively drawn beneath gate 40, rolls 4|, 42 lightly engage its emulsified surface and remove adhering drops of water or spread them into a thin uniform layer thus preventing spotting of the film while it is being dried, while guide flanges 4|, 42 assist in keeping the film in proper alignment as it enters the machine. It will be observed that a few rollers adjacent the brackets supporting receiving spool R are not engaged by belt 50 due to its passage over pulley 82 and so do not actively assist in moving the film but this is a matter of no consequence since by the time the leading end of the film has reached the first of these rollers, those over which it has already passed are applying adequate driving force to properly advance it. a

' It will be'apparent that until after the leading end of the film is connected with receiving spool R, the presence of an operator is intermittently so required but thereafter the action of the machine is entirely automatic and requires no supervision whatever, for when the end of the film on spool S is reached the pull of the film under the action of rollers 30 is ordinarily suflicient to detach it 40 therefrom, but should it be insufiicient for that purpose rollers 30 merely slip on the back of the film which remains stationary in the machine until the operator returns to it and detaches the rear end of the film from the said spool so it 45 can again be moved forward until its rear end finally reaches receiving spool R.

While I have herein described one form of the machine of my invention with considerable particularity, I do not thereby desire or intend to 50 restrict myself thereto in any way as numerous changes and modifications in the design, construction and arrangement of the various elements therein comprised may be made if desired, while the principles of. the invention applied 55 through the medium of instrumentalities other than those to which I have referred may be utilized for many industrial purposes other than the drying of photographic films and generally similar web-like articles without departing from If! the spirit and scope of the invention as defined in the appended claims. a Having thus described my invention, I claim and desire to protect by Letters Patent of the United States:

1. A machine of the character described comprising a generally cylindrical casing having a plurality of air nozzles arranged in circumferen tially spaeed relation about its periphery, a fan at the center of the casing adapted to draw air thereinto and expel it through said nozzles in generally radially directed jets of minimum dimension circumferentially of the casing and maximum dimension transversely thereof, means for driving the fan, and means for progressively moving the article to be dried about the periphery of the casing and supporting it in a defined path against pressure of said jets comprising a series of rollers, means supporting the rollers in annularly spaced relation about the casing in radially spaced relation thereto, means interconnected with the fan driving means for driving the rollers, and means for controlling the speed of the roller driving means independently of the speed of the fan.

2. In a machine of the class described, a cylindrical casing having a plurality of air nozzles in itsperiphery, means for projecting air through said nozzles in generally radially directed jets,

a series of rollers disposed in cage-like formation about the casing in spaced relation to the nozzles. and supporting and driving means therefor whereby the article to be dried when introduced to the cage over one roller is thereafter carried about the casing through its frictional engagement with the rollers induced by the pressure of the air jets on its surface proximate the nozzles, and a roll arranged outside and adjacent the first mentioned roller adapted to engage the opposite surface of the article to free it from accumulated fiuid prior to its reaching the zone of the first air jet. p

3. In a machine of the class described, a cylindrical casing having air nozzles in its periphery, means for projecting air through said nozzles, a series of driven rollers arranged in cage-like formation about the casing adapted to support and progressively move the article to be dried, a roll disposed adjacent and outwardlyof one of said rollers, and means supporting said roll in such manner it may be moved from normal position away from said roller to enable the article to be passed over the latter preparatory to its progressive movement within the cage and then returned thereto to engage that face of the article opposite that adjacent the casing to free it from accumulated fluid as the article is progressively drawn beneath the roll.

JOHN WESLEY SMITH. 

